Logical Rules for Sketch-Based Computer Modeling of Reservoir Stratigraphy: Application to Deepwater Siliciclastic Systems

Abstract

Conventional reservoir modeling workflows are poorly suited to rapid prototyping of reservoir model concepts, and testing of how these concepts might impact on reservoir behavior. An alternative and complementary approach to traditional workflows is to use sketch-based interfaces and modeling (SBIM) to allow rapid creation of prototype reservoir models. SBIM is a simple and intuitive approach for creating complex 3D geometries that has been adopted in a number of engineering and design fields but has yet to be applied in reservoir modeling. In SBIM, the user sketches lines in map or cross-section view and the lines are rapidly extrapolated to create parameterised surfaces. The extrapolation can be driven by an underlying conceptual model and/or be constrained by data or further sketched lines. A key requirement for efficient application of SBIM is a clear set of logical rules that govern how sketched lines are extrapolated to create surfaces, and how these surfaces interact. Here we present a suite of rules for stratigraphic surfaces that are based on or can mimic the law of superposition, Walther's Law, and sequence stratigraphy. They allow the user to work flexibly in creating computer models of reservoir stratigraphy. A fixed conceptual stratigraphic model does not have to be in mind at the outset of sketching; surfaces and their interactions can be added, removed or edited in any order. There is no need to sketch in stratigraphic order; indeed, the software interprets the stratigraphic ordering of the surfaces from the sketch. Input data can be sourced from seismic, geocellular or flow simulation models, outcrop analogues, conceptual model libraries, or blank screen, allowing a range of modeling scales and styles to be used. The rules are implemented within the software framework of Rapid Reservoir Modeling (RRM). The sketched surfaces bound volumes which can be meshed and gridded, thereby allowing geologic heterogeneities to control the mesh architecture of the models and rapid calculation of key reservoir properties. This work provides, for the first time, a framework for applying SBIM to the reservoir modeling workflow. The speed and ease of use of RRM enables multiple working interpretations to be developed from limited data, uncertainty to be readily appraised, and models and figures to be easily updated to incorporate new data or concepts. We demonstrate application of the logical rules through SBIM deepwater clastic examples.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016